Vapor-deposition apparatus

ABSTRACT

A vapor-deposition arrangement comprises a housing defining a vaporization compartment and an additional compartment communicating with the vaporization compartment via a communication opening. A drive unit moves a ribbon-like web of material, to be coated by vapor-deposition, across the communication opening, obstructing the opening and substantially separating the compartments from each other. An evacuating unit creates underpressure in the compartments. A vaporizing unit within the vaporization compartment creates a stream of vaporized material directed towards the communication opening. The vaporized material is deposited onto that side of the web facing the vaporization compartment, and condenses. The liberated heat of condensation vaporizes volatile substances carried by the web and releases such volatilized substance from that side of the web facing said additional compartment, and escapes into the additional compartment. The web at said opening is entrained about a roller guide member which is operatively part of said additional compartment and which closes said opening. Said member being of a non uniform peripheral surface whereby to facilitate said escape of the volatilized substance.

O United States Patent [1 1 [111 3,854,442

Adam et al. Dec. 17, 1974 VAPOR-DEPOSITION APPARATUS Primary Examiner-Morris Kaplan [751 Inventors: Helmut Adam; Alfred Ortlieb; Attorney, Agent, or FirmMichael S. Striker Eberhard Traub, all of Stuttgart, Germany [57] ABSTRACT [73] Assigneez Robert Bosch GmbH Stuttgart A vapor-deposition arrangement comprises a housing Germany defining a vaporization compartment and an additlonal compartment communicating with the vaporiza- 1 Filed! y 1972 tion compartment via a communication opening. A [21] APP] NO: 272,967 drive unit moves a ribbon-like web of material, to be coated by vapor-deposition, across the communication opening, obstructing the opening and substantially Foreign Application Priority Data separating the compartments from each other. An

Au 20, 1971 Germany 2141723 evacuating unit creates underpressure in the compartments. A vaporizing unit within the vaporization com- [52] US. Cl. 118/49 partment creates a stream of vaporized material di- [51] Int. Cl. C23c 13/08 rected towards the communication opening. The va- [58] Field of Search 1 18/48, 49, 49.1, 49.5; porized material is deposited onto that side of the web l17/lO7.1; 34/72, 130, 138, 139, 155, 159, 160 facing the vaporization compartment, and condenses. The liberated heat of condensation vaporizes volatile [56] References Cited substances carried by the web and releases such vola- UNITED STATES PATENTS tilized substance from that side of the web facing said 2,702,760 2/1955 Barth 118/49 x iddificmal compartment and 9 into 2945771 7/1960 Munsfeld H7/l06 R tional compartment. The web at said opening 15 en- 3971862 2/196] a]. 18/49 X trained about a roller guide member which is opera 2,996,037 8/1961 Eng 118/49 tively P Of Said additional Compartment and which 3.002.849 10/1961 Harmon ct 111.... 118/50 x closes said opening. Said member being of a non uni- 3,086.889 4/1963 Strong 118/49 X form peripheral surface whereby to facilitate said es- 3,227.l32 [/1966 Clough 8i. ill. 118/49 cape of [he volatilized 5ub5tance 3.531.319 9/l970 Martorana 118/48 X 6 Claims, 6 Drawing Figures 1 VAPOR-DEPOSITION APPARATUS BACKGROUND OF THE INVENTION The present invention relates to vapor-deposition arrangements.

More particularly, the invention relates to the vapordeposition coating of continuously moving webs, for instance ribbon-like webs which are unrolled from a pay-out reel, passed through a vaporization compartment, and then rolled up on a take-up reel.

Vapor-deposition arrangements of this kind usually comprise a vaporization compartment having an entry and an exit for a continuously driven ribbon-like web. A vaporizing unit within the vaporization compartment vaporizes a material, for instance a metal such as aluminum, and creates a stream of vaporized material directed towards the moving web. An evacuating unit maintains an extremely low pressure within the vaporization compartment.

In prior art versions of such arrangements, the ribbon-like web to be coated travels from a pay-out reel through one or more air-locks, then into and through the vaporization compartment where material is deposited onto one face of the web, then out of the vaporization compartment and through one or more further ai'rlocks, and finally onto a take-up reel. The air-locks are provided in the prior art to preserve the underpressure within the vaporization chamber, and also to prevent the entrance thereinto of undesired substances. The only undesired substances permitted to enter the vaporization chamber will be those expelled or released from the moving ribbon-like web itself. Specifically, the web as it enters the vaporization chamber may carry certain vaporizable or other substances which are vaporized due to the condensation heat liberated upon condensation of the vapor-deposited material. In the case of webs of hygroscopic material, such as paper, the vaporizable substance is water. As the material being vapor-deposited condenses upon one side of the ribbon-like web, the liberated condensation heat vaporizes the inherent moisture of the web, and the water vapor escapes, for example, from the side of the web not being coated by vapor-deposition. It is of course desirable to limit the vapors present in the vaporization compartment to those actually involved in the vapordeposition, and accordingly such water vapor and/or other substances, must continuously be evacuated from the vaporization compartment.

In the prior art, such removal of undesired vapors from the vaporization compartment is effected by means of vacuum pumps. However, it is inconvenient and costly to provide such pumps, to operate them and to provide the aforementioned plurality of air-locks. When the web is very hygroscopic, for instance, a very substantial amount of water vapor is released from the web into the vaporization compartment, and the aforementioned difficulties become particularly serious.

SUMMARY OF THE INVENTION It is accordingly the general object of the present invention to overcome these disadvantages of prior-art vapor-deposition arrangements.

It is a related object to provide a novel vapordeposition arrangement which overcomes such disadvantages.

Still more specifically, it is an object to provide such an arrangement wherein water vapor, or the like, re-

leased from the web due to the liberatedcondensation heat of the vapor-deposited material, is not released into the vaporization compartment.

It is a related object not only to prevent release of such vapors into the vaporization compartment, but thereafter also to prevent their subsequent entry into the vaporization compartment.

It is a further object to prevent the release of such vapors into the vaporization compartment, but without the use of air-lock arrangements or other complicated sealing devices.

It is a concomitant object to prevent the release of such vapors into the vaporization compartment by means of an extremely simple structure which adds nothing to the cost of the vapor-deposition arrange ment, and which can even reduce the cost of eliminating the need for air-locks between the vaporization compartment and the pay-out and take-up reels.

These objects, and others which will become more understandable below, can be met by a vapordeposition arrangement which comprises a housing defining a vaporization compartment and an additional compartment communicating with the vaporization compartment via a communication opening. Moving means moves a web to be coated across the communication opening in a sense obstructing the opening and substantially separating the compartments from each other. Evacuating means creates an underpressure in the compartments. Vaporizing means within the vaporization compartment creates a stream of vaporized material directed towards the communication opening for condensation upon the side of the web facing the vaporization compartment. Any volatile substance which, due to the liberated heat of such condensation, escapes from the web at the side thereof facing said additional compartment, enters such additional compartment, and is substantially prevented by the presence of the web itself from passing into the vaporization compartment through the aforementioned communication opening.

it is a particularly simple and advantageous expedient to separate the aforementioned vaporization and additional compartments from each other by a separating wall which defines the communication opening. Then the web, particularly if a ribbon-like web, can be passed over the opening, and will have such dimensions relative to the opening that the opening is completely obstructed by the web itself.

The novel features which are considered as characteristic for the invention are set forth in particular in the appended claims. The invention itself, however, both as to its construction and its method of operation, together with additional objects and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawing.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a somewhat schematic view of a vapordeposition arrangement according to the invention,

FIG. 2 is a section through the arrangement of FIG. 1, taken on line II-II of FIG. 1, and as seen in direction of the arrows at the end of line ll-Il;

FIG. 3 is a somewhat schematic view of another vapor-deposition arrangement according to the invention; and

FIGS. 4-6 are partial sectional views, taken on line IV-IV of FIG. 3, showing three different forms of the guide roller 33 of FIG. 3.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The vapor-deposition arrangement shown in FIG. 1 has a generally cylindrical housing including a separating wall 18 which divides the interior of the housing into a vaporization compartment 12 and an additional compartment 11. Compartments 11 and 12 communicate with each other via communication opening 18a in separating wall 18.

Moving means in FIG. 1 includes a pay-out reel 14, a take-up or drive reel 17, and guide rollers 15 and 16. As will be appreciated, drive reel 17 is driven by a nonillustrated motor, or the like. Moving means 14-17 is operative for driving an elongated ribbon-like web 13 across the communication opening 18a in a sense completely obstructing the opening 180, and thus separating vaporization compartment 12 from additional compartment 11. Accordingly, it is necessary that the web carrier means 14-17 be adapted to carry a web having a breadth sufficient to cover the opening 18a, and thereby seal compartments l1 and 12 from each other. This is particularly evident from FIG. 2, where the communication opening 18a is indicated in dotted lines.

Evacuating means E serve to evacuate compartments 11, 12 via evacuation passages 11a, 12a, so as to maintain the necessary underpressure in the compartments.

Advantageously, the vaporization compartment 12 and additional compartment 11 are separately evacuated.

Located within vaporization compartment 12 is a vaporizing means 20, which may be a simple crucible arrangement or any other type of conventional vaporizing arrangement. Vaporizing means 20 vaporizes a body of material 20, for instance a metal such as aluminum, and creates a stream of vaporized material 21 directed towards communication opening 18a, and thus towards the portion of web 13 passing across the communication opening. The vaporized material 20 is deposited upon that side of the web facing the vaporization compartment. As the vaporized material 20 condenses upon the surface of web 13, the temperature of such condensing material, and in particular the liberated heat of condensation, effects vaporization of the moisture within ribbon-like web 13. Depending on the web material, it may be that the substance in question is not moisture-Le, water--but another substance instead of or in addition to water. Likewise, depending on the material of the web, gaseous or other material within the carrier may be expelled from the carrier when the carrier is contacted on one side by the very hot vapor-deposited material 20. The water vapor, or other substance, is symbolized in FIG. 1 by three parallel arrows, and in fact passes out of the carrier from that side thereof facing the additional compartment 11, and passes into the additional compartment itself. Inasmuch as the moving web 13 completely obstructs communication opening 18a, and separates comparts l1 and 12 from each other, the presence of web 13 will all but completely prevent the escaping vapors 22 from finding entry into vaporization compartment 12. Thus the vapors within compartment 12 will be virtually exclusively those of the substance 20 to be vapordeposited, and the need for evacuating other undesirable vapors from compartment 12 is obviated.

The vapors 22 passing into additional compartment 11 are withdrawn therefrom by the respective evacuating means E. To hasten the evacuation, it is possible to provide a cooling trap 23 (indicated in broken lines in FIG. 1) at the side of the web 13 facing the additional compartment 1 l, and in the vicinity of the communication opening 18a. If such cooling trap is provided, the escaping vapors 22 will be condensed upon such trap, and can accordingly be withdrawn from compartment 11 in liquid form, if desired.

The obstruction of communication opening 18a by web 13 has the further advantage that the compartments ll, 12 are pneumatically separated from each other quite effectively, and thus in each compartment an underpressure need be maintained only to the degree actually necessary, since the underpressures in the two compartments will not be equalized.

The vapor-deposition arrangement of FIG. 3 is similar to that of FIG. 1. A generally cylindrical housing 30 has a separating wall 37 which divides the interior of the housing into a vaporization compartment 301 and an additional compartment 35. Vaporizing means 39 is located within vaporization compartment 301, and serves to generate and direct a stream of vaporized material 40 in direction towards communication opening 36 in separating wall 37.

The moving means of FIG. 3 differs somewhat from that of FIG. 1. In FIG. 3 the moving means includes a pay-out reel 32, a take-up or drive reel 34 and a generally cylindrical guide roller 33. A ribbon-like web 31 passes from the compartment 35, over roller 33 into compartment 301, and thence back into compartment 35. As before, vaporized material 40 is deposited on and condenses upon that side of web 31 facing vaporization compartment 301. Again as before, water vapor is released from the other side of web 31, namely that side facing additional compartment 35. And again, such released water vapor passes into additional compartment 35, instead of into vaporization compartment 301. The vapor passes into compartment 35 from the back of web 31, despite the fact that the back of web 31 is being supported on the surface of guide roller 33. This is because guide roller 35 has a generally cylindrical peripheral surface which is incomplete and which supports only portions of the back side of web 31. In this way, water vapor can escape from those portions of the back side of web 31 which are not being supported by roller 33. FIG. 6, for instance, illustrates a roller 33c having a plurality of generally cylindrical supporting surfaces 44 which engage the back side of web 31. However, the roller 330 also has a plurality of circumferentially extending inwardly recessed channels 43, which permit the back side of web 31 to communicate, via such channels, with additional compartment 35. Thus, vapors released from the back side of web 31 pass circumferentially along such channels and into additional compartment 35, but are prevented by the presence of the web itself from passing freely into vaporization compartment 301.

FIG. 4 illustrates a guide roller 33a having the same function, but having a generally cylindrical peripheral surface with a plurality of recessed portions arranged in waffle-like grid formation.

FIG. 5 illustrates another such guide roller 33b which is hollow, and which has a generally cylindrical peripheral support surface including a plurality of apertures, which permit the gases released from the back side of web 31 to pass into the additional compartment 35.

It will be understood that each of the elements described above, or two or more together, may also find a useful application in other types of methods and constructions differing from the types described above.

While the invention has been illustrated and described as embodied in an arrangement for the vapordeposition of metallic material onto a ribbon-like web, it is not intended to be limited to the details shown, since various modifications and structural changes may be made without departing in any way from the spirit of the present invention.

Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can be applying current knowledge readily adapt it for various applications without omitting features that, from the standpoint of prior art, fairly constitute essential characteristics of the generic or specific aspects of this invention and, therefore such adaptations should and are intended to be comprehended within the meaning and range of equivalence of the following claims.

What is claimed as new and desired to be protected by Letters Patent is set forth in the appended claims:

1. A vapor-deposition arrangement, comprising, in combination, housing means defining a vaporization compartment and an additional compartment communicating with said vaporization compartment via a communication opening; moving means for moving a web to be coated across said communication opening along a predetermined path so oriented with respect to said communication opening that a web moved by said moving means across said opening and along said path blocks said opening and separates said compartments from each other; evacuating means for establishing subatmospheric pressure in said compartments; and vaporizing means within said vaporization compartment for creating a stream of vaporized material directed towards said communication opening for condensation upon the one side of the web facing said vaporization compartment, whereby any volatile substance which, due to the liberated heat of said condensation, escapes from the web at other side thereof and into said additional compartment will substantially be prevented by the presence of the web from passing into said vaporization compartment through said communication opening, and wherein said moving means includes a generally cylindrical guide roller interposed between said compartments substantially closing said opening and adapted to guide and support a ribbon-like web at the side of the latter facing said additional compartment, and wherein the outermost peripheral surface of said guide roller is incomplete so that a web supported on said outermost peripheral surface will be engaged by said roller only at portions of its surface so as to permit passage into said additional compartment of volatile substances escaping from the unsupported portions of said other side of such web.

2. An arrangement as defined in claim 1, wherein said peripheral surface of said roller is inwardly recessed at a plurality of portions, whereby to accommodate any volatile substances escaping from said other side of said web.

3. An arrangement as defined in claim 1, wherein said peripheral surface of said roller includes a plurality of recessed portions arranged in waffle-like grid formation.

4. An arrangement as defined in claim 1, wherein said roller is hollow and wherein said has a peripheral surface includes a plurality of apertures.

5. An arrangement as defined in claim 1, wherein said peripheral surface includes a plurality of inwardly recessed circumferentially extending channels.

6. A vapor-deposition arrangement, comprising, in combination, housing means defining a vaporization compartment and an additional compartment communicating with said vaporization compartment via a communication opening; moving means for moving a web to be coated across said communication opening along a predetermined path so oriented with respect to said communication opening that a web moved by said moving means across said opening and along said path blocks said opening and separates said compartments from each other; evacuating means for establishing subatmospheric pressure in said compartments; and vaporizing means within said vaporization compartment for creating a stream of vaporized material directed towards said communication opening for condensation upon the one side of the web facing said vaporization compartment, whereby any volatile substance which, due to the liberated heat of said condensation, escapes from the web at the other side thereof and into said additional compartment will substantially be prevented by the presence of the web from passing into said vaporization compartment through said communication opening, and wherein said moving means includes a guide member interposed between said compartments substantially closing said opening and adapted to guide and support a ribbon-like web at the side of the latter facing said additional compartment, and wherein the web-supporting surface of said guide member is incomplete so that a web supported on said web-supporting surface will be engaged by the latter only at portions of the surface of said other side so as to permit passage into said additional compartment of volatile substances escaping from the unsupported portions of said other side of such web. 

1. A vapor-deposition arrangement, comprising, in combination, housing means defining a vaporization compartment and an additional compartment communicating with said vaporization compartment via a communication opening; moving means for moving a web to be coated across said communication opening along a predetermined path so oriented with respect to said communication opening that a web moved by said moving means across said opening and along said path blocks said opening and separates said compartments from each other; evacuating means for establishing subatmospheric pressure in said compartments; and vaporizing means within said vaporization compartment for creating a stream of vaporized material directed towards said communication opening for condensation upon the one side of the web facing said vaporization compartment, whereby any volatile substance which, due to the liberated heat of said condensation, escapes from the web at other side thereof and into said additional compartment will substantially be prevented by the presence of the web from passing into said vaporization compartment through said communication opening, and wherein said moving means includes a generally cylindrical guide roller interposed between said compartments substantially closing said opening and adapted to guide and support a ribbon-like web at the side of the latter facing said additional compartment, and wherein the outermost peripheral surface of said guide roller is incomplete so that a web supported on said outermost peripheral surface will be engaged by said roller only at portions of its surface so as to permit passage into said additional compartment of volatile substances escaping from the unsupported portions of said other side of such web.
 2. An arrangement as defined in claim 1, wherein said peripheral surface of said roller is inwardly recessed at a plurality of portions, whereby to accommodate any volatile substances escaping from said other side of said web.
 3. An arrangement as defined in claim 1, wherein said peripheral surface of said roller includes a plurality of recessed portions arranged in waffle-like grid formation.
 4. An arrangement as defined in claim 1, wherein said roller is hollow and wherein said has a peripheral surface includes a plurality of apertures.
 5. An arrangement as defined in claim 1, wherein said peripheral surface includes a plurality of inwardly recessed circumferentially extending channels.
 6. A vapor-deposition arrangement, comprising, in combination, housing means defining a vaporization compartment and an additional compartment communicating with said vaporization compartment via a communication opening; moving means for moving a web to be coated across said communication opening along a predetermined path so oriented with respect to said communication opening that a web moved by said moving means across said opening and along said path blocks said opening and separates said compartments from each other; evacuating means for establishing subatmospheric pressure in said compartments; and vaporizing means within said vaporization compartment for creating a stream of vaporized material directed towards said communication opening for condensation upon the one side of the web facing said vaporization compartment, whereby any volatile substance which, due to the liberated heat of said condensation, escapes from the web at the other side tHereof and into said additional compartment will substantially be prevented by the presence of the web from passing into said vaporization compartment through said communication opening, and wherein said moving means includes a guide member interposed between said compartments substantially closing said opening and adapted to guide and support a ribbon-like web at the side of the latter facing said additional compartment, and wherein the web-supporting surface of said guide member is incomplete so that a web supported on said web-supporting surface will be engaged by the latter only at portions of the surface of said other side so as to permit passage into said additional compartment of volatile substances escaping from the unsupported portions of said other side of such web. 